I would say POV of the humans. Simply because in order for the aliens to arrive here, they have to be much farther technically advanced than us.
From the aliens perspective, it would be like us going back a few hundreds years and look at a more primitive civilization. From the humans POV it would be more like looking into the future.
Just seems humans encountering a more highly advanced race of beings would be more interesting than them contacting a more primitive group of beings.